Kinesthetic control simulator

ABSTRACT

A kinesthetic control simulator having a flat base upon which rests a support structure having a lower spherical surface for rotation on the base plate with columns which support a platform above the support structure at a desired location with respect to the center of curvature of the spherical surface. A handrail is at approximately the elevation of the hips of the operator above the platform with a ring attached to the support structure which may be used to limit the angle of tilt. Five degree freedom-ofmotion can be obtained by utilizing an air pad structure for support of the control simulator.

United States Patent Hill et all.

KINESTHETIC CONTROL SIMULATOR Inventors: Paul R. Hill; David F. Thomas,Jr.,

both of Hampton, Va.

The United States of America as represented by the Administrator of theNational Aeronautics and Space Administration, Washington, DC.

Filed: Apr. 20, 1970 Appl. No.: 29,979

Assignee:

US. Cl. 35/12 C, 272/1 R, 272/57 A Int. Cl. G091) 9/08 Field of Search35/12 R, 12 C, 12 E, 12 P;

272/1 B, l C, 1 R, 33 R, 33 A, 57 A, 60

3/1962 Coplin et a1. 11/1966 Johnson 35/12 C Richter et a1 35/12 PCudmore 272/1 R X Primary ExaminerRichard C. Pinkham AssistantExaminer-R. T. Stouffer Attorney, Agent, or FirmHoward J. Osborn; JohnR. Manning [57] ABSTRACT A kinesthetic control simulator having a flatbase upon which rests a support structure having a lower sphericalsurface for rotation on the base plate with columns which support aplatform above the support structure at a desired location with respectto the center of curvature of the spherical surface. A handrail is atapproximately the elevation of the hips of the operator above theplatform with a ring attached to the support structure which may be usedto limit the angle of tilt. Five degree freedom-of-motion can beobtained by utilizing an air pad structure for support of the controlsimulator.

3 Claims, 6 Drawing Figures PATENTED JAN 1 4!.975

SHEET 10F 3 wm wm mm 1/ mm an E o L mm om mm mm a g 3 WV.

mm 2 E INVENTORS PAUL R. HILL BY DAVID F. THOMAS, JR.

ATTORNEY PAIENIED AN 3.859.736

sum 2 0! INVENTORS PAUL R. HIILL BY DAVID F. THOMAS, JR.

ATTORNEY PATENTED 1 41975 3. 859.736

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72 in 15 m INVENTORS PAUL R. HILL Y DAVID F. THOMAS, JR.

, ATTORNEY KINE STI'IETIC CONTROL SIMULATOR ORIGIN OF THE INVENTION Theinvention described herein was made by employees of the U.S. Governmentand may be manufactured and used by or for the Government forgovernmental purposes without the payment of royalties thereon ortherefor.

BACKGROUND OF THE INVENTION This invention relates generally tosimulators and more particularly to a kinesthetic control simulator forexperience in multiple degree freedom of movement.

Previous devices utilized a balancing platform free to rotate about onehorizontal axis. Rotation of the platform was used as input to anautomatic servo system to drive the platform along a horizontal trackperpendicular to the axis of platform rotation. This device failed tooperate satisfactorily in that it did not simulate the attitude controlof a flying platform because rotation was restricted to motion about oneaxis. Moreover, the platform size greatly restricted the operators feetand the control feel of the device did not correspond to previousexperiences with actual flying platforms.

It has also been known to utilize devices on which the operator wasfirmly attached by straps or other means and which used, for example, anair cushion to provide a degreeof weightless simulation and the operatorwith a feel for three-dimensional movement. These devices obviouslyhavethe disadvantage of being large and cumbersome and requiring expensiveconstruction, as well as critical operating procedures. It has also beenknown to utilize mechanisms having air cylinders to provide an aircushion for suspension of the vehicle above the floor surface with theoperator standingin a spherical portion which is mounted for freerotation. This construction would permit three degrees of freedom;however, it fails to give the operator a true indication of feel atleast partially caused by the requirement for manual control by theoperator of a reaction gun. Furthermore, the operation of the device islimited through the amount of air that can be stored within the chamberon the vehicle or the vehicle movement limited by some type of conduitfor conveying pneumatic pressure for the air cushion.

Wherever kinesthetic control is used herein the term refers to controlby the sense whose end organs lie in the muscle, tendons and joints andwhich are stimulated by bodily movement and tensions; also known as themuscle means. Kinesthetic alternatively is the type of sensoryexperience derived from the sense having its end organs lying in themuscles, tendons and joints.

It is an object of the instant invention to provide a large radius,spherical surface for rotational control for attitude simulation of aflying platform.

Another object of this invention is to provide an inexpensive readilyavailable device for simulation of kinesthetic control such as would beused in operating vehicles similar to a lunar flying platform.

Another object of the instant invention is to provide a simulator whichcan be utilized for studying engineering parameters such as inertia,platform size and control location needed for the design of both thesurfaceto-surface and the surface-to-orbit type vehicles.

Still another object of the instant invention is to provide a safe,simple, inexpensive, yet accurate, simulator for astronaut training.

A still further object of this invention is to provide a sphericalsurface for rotation upon a base with a standon platform for support ofthe operator and which is supported above the spherical surface toprovide simulation of a flying platform.

Yet another object of the instant invention is to pro vide a kinestheticcontrol simulator having five degrees freedom of motion effected byutilizing an air pad structure for support of a control simulatorwherein columns connect a stand-on platform to a spherical lowersurface.

A more complete appreciation of the invention and many vof the attendantadvantages thereof will be readily apparent as the same becomes betterunderstood by reference to the following description, when considered inconnection with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of the instant invention;

FIG. 2 is a side elevational view of an alternative embodiment of theinvention;

FIG. 3 is a diagrammatic view for analysis of a rocket powered devicesimilar to the instant invention,

FIG. 4 is a diagrammatic view for analysis of the simulation device ofthe instant invention;

FIG. 5 is a side elevational view, with portions omitted for clarity, ofa modified embodiment of the instant invention; and

FIG. 6 shows an isometric view of an air support system for the controlsimulator of the instant invention.

Referring now to the drawings and more particularly to FIGS. 1 and 2wherein the instant inventive simulator 10 is shown as including base 12having upper surface 14 on which rests the lower spherical surface 18 ofsupport 16 that also includes upper surface 20. Columns 22, FIG. 1, arerigidly secured to surface 26 of platform 28. Platform 28 is thestand-on support for the operator of the instant inventive simulator l0.

Framework 30 is rigidly secured to platform 28 and extends upwardlytherefrom utilizing vertical frame 32. Handrail 34 extends around theoperator substantially parallel to platform 28 and at approximately theelevation of the hips of the operator. Horizontal top frame 36 securesthe upper ends of vertical frame 32 and supports counterweights 40 for apurpose to be more fully understood hereinafter. As an option in FIG. 1embodiment, counterweights 58 may also be added to support 16, thepurpose of which will be explained subsequently.

Center-of-curvature 42 of spherical surface 18 is located in FIG. 1 atapproximately the elevation of the waist of the operator.Center-of-gravity 44 is established by the combined mass of the operatorand simulator 10 structure and should substantially coincide withcenter-of-curvature 42 for zero stability.

Tilt ring 50 permits a maximum degree of rotation of simulator l0 and isattached to platform 28 and support 16 by braces 52. I

The alternative embodiment of the invention shown in FIG. 2 issubstantially identical to that shown in FIG. 1 with the exception thatplatform 28 is spaced a greater distance from flat upper surface 20 ofsupport 16 by elongated columns 56. It is to be noted that columns 56could be of a telescopic construction for use "configurationtherebetween.

A lock pininserted into coinciding apertures or a similar locking'device could be utilized to adjust the height of platform 28 abovesurface 20. It is to be noted that the alternative embodiment is notprovided with the full framework shown in FIG. 1, which would includecounterweights 40, but framework 32 stops at handrail 34. Center ofgravity 46, FIG. 2, substantially above the center-of-curvature 42 ofspherical surface 18, is that of only the operator and does not includethe simulator structure.

An alternative embodiment of the invention would utilize a structuresimilator to that of either FIGS. 1 or 2 but weights 58 would beattached to. the surface of support 16 to provide a more stable butactive device. It is only necessary that weights 58 be located belowcenter-of-curvature 42. The greater the amount of weight added thegreater will be the effort required to rotate the device to thus providethe exerciser or gymnastic equipment.

Referring now to FIG. 3 wherein is shown a diagrammatic analysis of arocket powered platform at an initial angle, beta, with respect to someexternal reference 88 such as the horizon and which the operator desiresto return to a level attitude such that beta equals zero degrees. Toaccomplish this, kinesthetic control calls for the operator to maintainhis center-of-gravity above the center of the platform with respect toexternal reference 88, the horizon. The reactive force on the man isequal to the mass of the man times the acceleration created by therocket, F ma. The control moment created by this reaction is equal tothe reactive force, times the moment arm, M Fl sin 8. In this expressionF is the reactive force, 1 the distance from the center of the platformto the operators center-of-gravity, and 8 is the kinesthetic controlangle, see FIG. 3. If a in the force equation, F ma, is equal to theacceleration of gravity then F W, the weight of the man, and the momentequation reduces to M W 1 sin 8.

As seen in FIG. 4, the platform simulator is at an initial angle, beta,with respect to external reference 88, the horizon, and it is desired toreturn the platform to a level attitude, beta equals zero degrees. Toaccomplish this reorientation, kinesthetic control calls for theoperatorto stand erect, moving his center-of-gravity 46 from point A topoint B through the control angle 8. Simulator 10 is mass-balanced byweights 40, see FIG. 1, which put its center-of-mass atcenter-of-curvature 42. Therefore, no gravity moments are created onsimulator 10 as a result of tilting; only inertia moments are present.Gravity moments are put in only by the operator and are equal to hisweight W times the horizontal distance b between the vertical actionline of his weight passing through center-of-gravity 46 at point B andthe line-of-action of the floor reaction F which is directly below pointA. From the right angle triangle with base b, hypotenuse land acuteangle beta, the following relation may be written: b =l sin [3, see FIG.4. Since 8 is equal to B, the expression may be written as b 1 sin 8.The righting moment, therefore, is:

which is exactly the same as for the rocket powered platform, whateverthe value of 8. Thus the kinesthetically induced reactions of anoperator of the simulator are equivalent to those of an operator of anactual air pressure from a source, not shown, to nozzles 60 for releaseto establish a thrust, T, which is always aligned with the axis ofsimulator 10 such that a horizontal accelerating force equal to T sin Bis provided to give horizontal translation in any direction. Platform 28is shown as mounted on four air pads 74 which utilize the pneumaticpressure from four motorized blowers 76 to support the entire simulatoron a smooth level floor permitting relatively frictionless translationin a plane and a total of five degrees of motion freedom. The simulatorin this configuration has two degrees of translational freedom across afloor or the like as well as three degrees of rotational freedomincluding rotation about a vertical axis and freedom to tilt in alldirections from the vertical. The device as shown in FIG. 5 relates onlyto a translational device and not to a nontranslational configuration asshown in FIG. 1 wherein it is critical to have the center-of-gravity andthe center-ofcurvature at an identical location for zero staticstability. Utilization of the translational system of FIG. 5 permitsinvestigation of situations where stabilizing gear, such as gyros, canbe located on control simulator 10, as seen in FIG. 2 by providing acombined center-ofgravity with respect to the center-of-curvature. Inthe translational system investigators are primarily interested in zerostability, but there must be slight static stability, to compensate forthe inertia of the dolly, as seen in FIGS. 5 and 6, in the translationalembodiment. It is possible to vary the static stability to investigatethe capability of an operator to compensate for stabilizing gear onboard simulator 10.

More detail of the translational support system is shown in FIG. 6 forproviding five degress of freedom of motion for control simulator 10. Inthe FIG. 6 embodiment dolly 78 includes enlarged base which has conduitlegs 72 attached thereto which extend downwardly to terminate at pads74. Power supply means, such as squirrel cage motors 76 are attached tothe undersurface of enlarged base 70 and provide a source of airpressure which flows through conduit legs to pads 74 to maintainpneumatic support of dolly 78. A source of power supply such aselectrical current could be provided by some external source in whichcase it would be merely necessary to have one electrical conduit, notshown, extending from dolly 78 to the source of the electrical currentor a portable supply, such as batteries, not shown, could be mounted ondolly 78.

OPERATION To operate simulator 10 the operator, while standing onplatform 28, utilizes whatever body motions are necessary to producedesired platform rotations. In the embodiment of the invention shown inFIG. 1 kinesthetic control simulator 10 is balanced aboutcenter-ofcurvature 42 of spherical surface 18, by means ofcounterweights 40 attached to framework 30. Stand-on platform 28 islocated with respect to center-of-curvature 42 of spherical surface 18such that center-of-gravity 44 of the simulator including the weight ofthe operator standing in the normal upright attitude coincides withcenter-of-curvature 42. This arrangement provides the neutral, zero,stability in the simulation device that is also present in a flyingplatform.

The second embodiment of the instant invention provides a variablestability capability which is of value in demonstrating kinestheticcontrol to those unacquainted with the flying platform. In theembodiment shown in FIG. 2 the length of columns 56 is increased toproduce a decrease in stability of the operatordevice combination. Inthis configuration counterweights 40 are removed from simulator 10.However, columns 56 elevate the center-of-gravity of the simulator to aposition at or slightly above the center-ofgravity 42. Location ofcenter-of-curvature 42 approximately at the surface of stand-on platform28 establishes a nearly neutral or slightly negative stability for thecombination depending upon the stature and weight of the operator.

A further alternative embodiment of the instant invention involves theuse of a lightweight construction in conjunction with a rugged maximumtilt ring 50 which would make simulator it) useful as an item ofplayground equipment. Furthermore, the elimination of columns 22 and 56and the addition of weights 58 to spherical surface 18 would increasethe positive stability of the device and adapt it for use as an item ofgymnasium equipment. The two variations of this alternative embodimentof the instant invention provide a potential use as body buildingexercisers for arm and leg muscles.

The embodiment of the invention as shown in FIGS. 5 and 6 relates to atranslational embodiment having five degrees of freedom of motionavailable due to the suspension of kinesthetic control simulator 10above the surface upon which it would normally operate. Thus, in FIG. 5is shown a construction having four air pads which would utilize powersources 76, for example four electric motors or gasoline engines, forproviding a pneumatic source of supply for an air cushion to maintainsimulator 10 in a position for complete freedom in the variousattitudes. Nozzles 60 provide downward thrust and also permit theoperator to have translational control.

The embodiment shown in FIG. 6 operates similar to that of FIG. 5;however, a plurality of pads 74 are utilized for support for dolly 78which has enlarged base 70 for receiving simulator 10 with base 12thereon.

Thus it is seen that the instant invention has advantages overpreviously known devices in simplicity and realistic simulation of aflying platform. It is to be noted that the novel simulator disclosedherein can be produced inexpensively and requires little or nomaintenance. It is possible to alter the construction from theembodiment shown in FIG. 1 to that of FIGS. 2, 5 or 6 in a very minimaltime period. The device, furthermore, requires no external power sourceand because it utilizes only the operator for any type of power, it isavailable on demand. Moreover, the instant simulator provides a readilyavailable and accessible device for observation of many problems ofscientific interest such as high momentof inertia configuration,instrument handling qualities and multipassenger-carrying capability.For example, the novel simulator is able to assist in investigations todetermine the passenger carrying capability of a lunar flyer. It hasbeen established that the operator can carry either one or twopassengers without difficulty with the construction of the instantinvention. Moreover, a control simulator having five degrees of freedomof motion is instantly available simply by mounting the simulatorstructure on a dolly such as shown in FIGS. 5 and 6.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A kinesthetic control simulator comprising:

support means having a spherical lower surface;

base means for support of said support means;

a platform mounted in spaced relation to said support means forsupporting an operator;

framework means extending upwardly from said platform; and

means for vertically positioning the center of gravity of the simulatorand an operator above, below and corresponding to the center of rotationof said spherical lower surface wherein said means for verticallypositioning includes column means for spacing said platform from saidsupport means and for vertically positioning the center of gravity ofthe simulator and an operator relative to the center of rotation of saidspherical lower surface whereby the simulator may simulate a stable,unstable and neutrally stable flying platform.

2. The simulator of claim 1 wherein said means for verticallypositioning includes a first removably counterweight means attached tosaid framework means and a second removable counterweight means attachedto said support means, said first and second counterweight means forvertically positioning the center of gravity of the simulator and anoperator relative to the center of curvature of said spherical lowersurface.

3. The simulator of claim 2 including pneumatic support means for thesimulator, whereby five degrees freedom of motion is provided forsimulation of a powered, flying platform.

1. A kinesthetic control simulator comprising: support means having aspherical lower surface; base means for support of said support means; aplatform mounted in spaced relation to said support means for supportingan operator; framework means extending upwardly from said platform; andmeans for vertically positioning the center of gravity of the simulatorand an operator above, below and corresponding to the center of rotationof said spherical lower surface wherein said means for verticallypositioning includes column means for spacing said platform from saidsupport means and for vertically positioning the center of gravity ofthe simulator and an operator relative to the center of rotation of saidspherical lower surface whereby the simulator may simulate a stable,unstable and neutrally stable flying platform.
 2. The simulator of claim1 wherein said means for vertically positioning includes a firstremovably counterweight means attached to said framework means and asecond removable counterweight means attached to said support means,said first and second counterweight means for vertically positioning thecenteR of gravity of the simulator and an operator relative to thecenter of curvature of said spherical lower surface.
 3. The simulator ofclaim 2 including pneumatic support means for the simulator, wherebyfive degrees freedom of motion is provided for simulation of a powered,flying platform.